Effects of the tacticities of poly(vinyl alcohol) on the structure and morphology of poly(vinyl alcohol) nanowebs prepared by electrospinning

Abstract

The effects of tacticities on the characteristics of polyvinyl alcohol) (PVA) nanowebs prepared by an electrospinning technique were investigated. PVA webs composed of uniform nanofibers with syndiotactic dyad (s-dyad) contents of 53.5 and 57.3% were successfully obtained with electrospinning. By changing processing parameters such as the initial polymer concentration, applied voltage, and tip-to-collector distance, we found suitable conditions for forming PVA webs with uniform nanofibers. PVAs of higher s-dyad contents were prepared at a lower solution concentration and at a higher applied voltage because of the easy formation of syndiotactic PVA chain entanglements at a very low polymer concentration. The average diameter of the nanofibers in a PVA web with the higher s-dyad content of 57.3% (ca. 240 nm) was thinner than that of the nanofibers in a PVA web with the lower s-dyad content of 53.5% (ca. 270 nm). In addition, the crystallinity and thermal stability were greatly increased with an increase in the s-dyad content. © 2007 Wiley Periodicals, Inc.